Pneumatic tool.



A. H. TAYLOR.

PNEUMATIG TOOL.

Puma-T1011 FILED :91:13.11 1910.

Patenteaauly 29, 1913.

.ALBERT H. TAYLOR, or EASTON', PENNSYLVANIA, assioma To ntenasoLL-a COMPANY, 0F NEW YORK, N. Y., A OORPOBTION OF PNEMA'TIC TOOL.

Lesen/12.

Specification of Letters Patent.

Patented July-29, 491:3;

Application med February 1'7, i910. seria'1N0.=544;4s4.

To all whom t may concern:

Be it known that I, ALBERT H. TnYLoR, a citizen of the United States, and resident of Easton, in the county of Northampton and State of Pennsylvania, have lnvented a new and useful Improvement in Pneumatic Tools, of which the 'following is a speclication.

This invention relates to a pneumatic tool in whichthe motive fluid, vfor example, compressed air, which `operates the hammer piston is controlled by a reciprocating valve mounted in the end of the cylinder, the pressure of the Imotive liuid on the oppos1te ends of the valvebeing under the control of the hammer piston. 0 n

A practical embodiment of the'lnventlon is represented in the accompanymg drawings in which,

4Figure 1 is a view in longitudinal section through a pneumatic tool, showing the ham mer piston at'th'e forward end of its stroke, Fig. '2 is a transverse section in the plane of the line A-A of Fig. 1, and Fig. 3 is a partial llongitudinal section `sllowing the hammer piston in 'a'rearward position.

The handle" of the tool is denoted by 1, its cylinder by 2 and its hammer piston by 3. The' hammer pistol? chamber 4 is provided intermediate its en s'with an exhaustport 5 leading through the cylinder wall to external atmosphere, which `exhaust port is alternately closed and opened to the front and rear of the hammer l' iston as the piston reciprocates. A lcylin rical imperfo'rate cupshaped slide valve' 6, in the presentjinstance, a hollow cylinder, is fitted to reciprocate lengthwise of the tool within an enlargement. of the piston chamber 4, at the rear end of the cylinder, a plate 7 being interposedbe` tween the rear end of the cylinder and the handle. The parts are so constructed and arranged that the piston 3 may enter and cushion inthe said cup-shaped valve-6. A chamber 8 surrounds the rear end of the cylinder 2, which chamber is provided with an exhaust port 9 leading throughthehandle wall toexternal atmosphere.

The motive Huid feed passage 10' in the handle l, is manually opened and closed by the usual throttle valve 11 and trigger 12. An air inlet passage 13 leads through the plate 7 and into the wall at the rear eind of the cylinder 2', which passage is provided with ya port 14 opening to the vface o the valve 6. The motive fluid is allowed to enter a chamber 15 at the back of the valve 6, through an inlet port 16 extending through the plate 7 and is 'allowed to escape from the i 'chamber l5 through an outlet .port I17 which extends within the plate 7 toward'the outer tace of the same and thence extends through the plate 7 into the wall of the cylinder 2 'and longitudinally Aalong the wall of the cylmder 2 to a ,point 17* where it opens into the interlor of 'the hammer piston chamber 4. The point 17 t 'where the lpo'rt I17 opens into the hammer piston chamber 4, is preferably located a distance'ba'ok l end of the chamber 4equal to aboutone-'h'alf the length of the hammer piston so that the port 17 will be closed bythe hammer piston when in its `forward position as shown in Fig. 1, and will beopened after the piston has moved half its lengthor thereabout on its backward stroke. l

rhe front of the valve 6 is 'at all'times in open communication with the hammer piston chamber 4, 'at'the back of the hammer piston 3. y

An exhaust vpassage 18 leads from the face of the valve 6to the chamber 8. An-

from the4 forward other passagel) leads from the face of the valve 6 longitudinally along within the wall of the cylinder 2 to the front end of the hammer piston chamber 4. A circumferentialport 2'0 in the valve 6 serves to open communication from the 'air inlet port 14 to the passage 19 when the valve 6 1s atthe'lim'it of its forward movement and to open communication from the passage 19 to vexternal the exhaust passage 18, haust port 9 when the valve is at the limit 'of its rearward movement. The valve 6 is also soform'edthat when at the limit of its forward movement, communication from the air inlet port 14' to the chamber '4 back of the hammer piston 3 is closed and when at the limit ovits rearwardmovement cominhumation the inlet port 14 'and the chamber 4 back of the hammer piston 3 is opened. y

In operation, suppose 'the hammer piston 3v to be located at 'the `forward end of its stroke, as shown in Fig. '1, and the valve 6 at the forward limit o its stroke opening communication throu-'gh its annular port '20 between the inlet 'passage A13, port 14'and passage 19 tothe ftront end 'ot 'the hammer atmosphere through chambe'r` 8 and eX- 10 f rearward movement. During this start-ing valve 6 at the limit of its forward stroke.

y Y This will permit the motive fluid to pass through the -port 14 and annular port.20 to v the passage 19 leading to the front of the piston 3 'and will start the piston 3 on its movement of the hammer piston 3, the hamlmer piston chamber 4 will be relieved of pressure by the port 5. Soon after the hammer piston 3 closes the port 5 and begins to compress the air in the chamber 4 at the rear of the piston, the port 17 will be opened to the hammer piston chamber 4 in front of :the hammer piston at the point 17*, so that as pressure accumulates in the hammer piston chamber 4 at the rear of the piston 3, it will be reduced in the chamber 15 at the back of the valve 6 untilas .the hammer piston 3 f lnears the limit of its rearward stroke, the

- ressure'in front of the valve 6 will over- Ealance the pressure to the rear of the valve 6 and the latter will be thrown rearwardly I -into the position shown in Fig. 3.` This movement of'the valve'6 will open the inlet passage 13 through the port 14 to the hammer piston chamber 4 at the rear of the hammer piston and will 'start the hammer plston on its forward or driving stroke. During the early part tf this stroke, the' hammer piston chamber 4 will be relieved of pressure in front the hammer plston both through the port, 5 and also through the passage 19 which .communicates through the annular port 20 in the valve with the port 18, chamber 8 and port 9 with the external atmosphere.

chamber 4 in front of the hammer piston 'will still be open to atmosphere through the' passage 19 and the ports above stated, and as ythe hammer piston 'passes the point 17* and delivers its stroke, the closure of the ort 17 will cause pressure to accumulate in l' the chamber 15 back of the valve 6, while pressure in front of the said valve will be relieved through the port 5 and the valve 6 will be promptlyv thrown forward into the vposition shown in Fig. 1, when the chain of operations `hereinabove enumerated will be i repeated.

The full pressure of the motive fluid momentarily upon the back of the valve 6 tends to throw it forwardly with great pnomptness, while the relief of this pressure is provided for at the proper time to permit the valve to .be thrown promptly rearward.

What I claim is:

1, In a pneumatic tool, a piston, its chamber, an imperforate cu -shaped valve open toward the piston cham er whereby the piston may enter the valve and' cushionthcre- After passing the port 5`` the' in, the valve chamber, a fluidusupply source, ports .opened and closed by said valve for controlling the operation of the piston and separate reduced ressure and exhaust ports ber, an imperforate cup-shaped valve open toward the piston chamber whereby the piston may enter the valve and cushion therein, the valve chamber forming an extension of the rear end of the piston chamber, a fluid supply source, ports opened and closed by said valve for controlllng the operation of the piston and separate reduced pressure and exhaust ports leading from the back of the valve chamber respectively to the supply source and to a point adistance back from the front end of the piston chamber 'whereby the valve is thrown forwardly by a constant reduced pressure and rearwardlv by the compression of air between the valve and piston.

3. In a pnuematic tool, a piston, its cham- A .ber,.an imperforate cup-'shaped valve open toward .the piston chamber whereby the pis- A.ton may enter tlle valveand cushion there- 1n, the valve chamber, a fluid supply source',

ports bringing the vpiston and valve -chambers Into communication vwith each other, the fluid supply source and external atmosphere, said valve vhaving a single port for opening and closingcommunication between the front end of the piston chamber, the supply source and external atmosphere, the front end of said valve also serving to open and close communication between the rear end of the piston chamber and the supply ico source and separate reduced pressure and y exhaust port-s leading from the back of the valve chamber, respectively, to the supply source and to a point a distance back from the front end of the piston chamber Whereby the valve is thrown forwardly by a con.- stant reduced pressure and rearwardly by the compression of air between the valve and piston. v

4. In a-pneumatic tool, a piston, its chamber, an imperforate cup-shaped valve open toward the piston chamber whereby the piston may enter the valve and cushion therein, the valve chamber forming an extension.

5 separate reduced pressure'and exhaust ports leading from the back of the Valve cha1n- .ber respectively to the supply source and to a point a distance back from the front end of the piston Chmberwhereby the valve is 10 thrown forwardly by .a constant reduced pressure and rearwardly by the compression of air between the valve and piston.

In testimony, that I claim the foregoing as my invention, I have signed my name in presence of two witnesses, this 14th dayof 15 February, 1910.

ALBERT H. TAYLOR. /Vitnesses:

RUSSELL H. WILHELM, GEO. J. HARTMAN.

Copies of this-patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

